s1 = input('请输入')
s2 = input('请输入')
s3 = input('请输入')
len1 = len(s1)
len1 = len(s2)
len1 = len(s3)
maxlen = len1
if  len2 > maxlen:
      maxlen = len2
if  len3 > maxlen:
      maxlen = len3
print('最大长度是',maxlen)

